Walk power mower with transmission providing both forward and reverse propulsion

ABSTRACT

A walk power mower having a cutting deck supported upon the ground by a front and rear wheel(s). The mower includes a traction drive system incorporating a bidirectional transmission adapted to propel the mower alternatively in both forward and reverse directions. In some embodiments, the mower may include a single bidirectional transmission (e.g., powering only rear wheel(s) or only front wheel(s) of the mower), while in other embodiments, two bidirectional transmissions may be provided to power both the front and the rear wheel(s). In other embodiments, the mower may include a bidirectional transmission powering the rear wheel(s), while the front wheel(s) may be attached to the deck via a caster assembly.

This application is a continuation of U.S. patent application Ser. No.15/624,116, filed Jun. 15, 2017, which is a continuation-in-part of U.S.patent application Ser. No. 15/472,415, filed Mar. 29, 2017, both ofwhich are incorporated herein by reference in their respectiveentireties. Moreover, U.S. patent application Ser. No. 15/195,648, filedJun. 28, 2016 and issued as U.S. Pat. No. 10,039,229 B2 on Aug. 7, 2018,is also incorporated herein by reference in its entirety.

TECHNICAL FIELD

Embodiments of the present disclosure relate to a walk power mower forcutting grass and, more particularly, to a transmission providing bothforward and reverse propulsion.

BACKGROUND

Walk power mowers are well known for cutting grass. For example, suchmowers are commonly used by property owners, such as homeowners, to cuttheir lawns. Such mowers have a cutting deck that houses a rotary grasscutting blade. The deck is supported by a plurality of wheels forrolling over the ground. A handle extends upwardly and rearwardly fromthe deck. A user who walks on the ground behind the deck grips a handlegrip of the handle to manipulate and guide the mower during a grassmowing operation.

It can be difficult or is undesirable for some users to manually push awalk power mower over the ground in order to cut one's lawn. It istiring to do so, particularly when the area being mowed is either large,hilly, or both. Thus, many mowers have traction drive systems thatutilize part of the power generated by the prime mover carried on themower to drive at least one pair of the mower's wheels, either the frontwheels or the rear wheels, in a forward direction. Such a self-propelledmower relieves the user of the necessity of having to bodily push themower over the ground. This greatly eases the physical effort requiredfrom the user in mowing one's lawn. The user now primarily guides orsteers the mower during the powered forward motion provided by thetraction drive system and the prime mover.

There are times when mowing one's lawn when the user needs to pull themower in reverse at least over short distances. For example, when a usercuts grass under the branches of a bush, the user will ordinarily drivethe mower forwardly so that the cutting blade reaches under the branchessufficiently to cut whatever patch of grass lies beneath the branches.However, once this patch of grass is cut, the user must pull back on thehandle to pull the mower out from under the branches of the bush. Whilethe traction drive system is designed with a one-way clutch to allow thedrive wheels to free-wheel during reverse motion so that the user is notpulling back against the resistance provided by the gearing in thetraction drive system, the drive wheels of the mower are typicallyunpowered during this reverse motion.

As a result, many users end up having to manhandle or wrestle the mowerback in this reverse motion scenario. This requires the user to expendphysical energy and for some users accomplishing manual reverse motionof the mower may be difficult or impossible in some situations. Thisdifficulty is exacerbated for those users in which trimming operationsrequiring reverse motions of the mower are numerous or are required ondifficult terrain. For example, in trimming beneath a bush, pulling backon the mower is even more difficult if the user has to pull the mowerback up a slope to get it out from under the branches of the bush.

Another problem sometimes present during reverse mower movement isunintentional lifting of the mower's front wheels. That is, when apulling force is applied at the offset mower handle, a moment isproduced that causes the mower to rotate about a line of contact betweenthe ground and the rear wheels. As one can appreciate, this rotation maycause the mower's front wheels to lift. While such lifting of the frontwheels may be beneficial for various mower operations (e.g., turning),maintaining front wheel engagement with the ground during reverse may beadvantageous (e.g., to maintain quality of cut).

SUMMARY

On aspect of this disclosure relates to a walk power equipment unithaving a housing supported upon the ground by at least a front wheel anda rear wheel, the housing adapted to traverse the ground in both aforward direction and an opposite, reverse direction. The powerequipment unit further includes a handle having a handle memberextending upwardly and rearwardly from the housing, wherein the handlemember includes: an upper end; and a lower end, the lower end attachedto the housing. A prime mover is carried by the housing, as is avariable speed traction drive system. The traction drive systemincludes: a bidirectional transmission operatively connected to a drivewheel selected from the group comprising the front wheel and the rearwheel, the transmission operable to selectively rotate the drive wheelto propel the housing over the ground; and a control system comprising ahandle grip translatable along the handle member. The handle gripactivates the transmission to power the drive wheel for movement of thehousing in the forward direction when the handle grip is translateddownwardly along the handle member from a neutral position, and thehandle grip activates the transmission to power the drive wheel formovement of the housing in the reverse direction when the handle grip istranslated upwardly along the handle member from the neutral position.

In another aspect of the present disclosure, a walk power mower isprovided that includes a deck supported upon the ground by front wheelsand rear wheels, the deck adapted to traverse the ground in both aforward direction and an opposite, reverse direction, wherein the frontwheels and/or the rear wheels operate as powered drive wheels of themower. The mower also includes a handle comprising a handle memberextending upwardly and rearwardly from the deck, wherein the handlemember includes: an upper end; and a lower end, the lower end attachedto the deck. A prime mover is carried by the deck and operativelyconnected to a cutting member associated with the deck. A variablespeed, bidirectional transmission is also carried by the deck, whereinthe transmission selectively rotates at least one of the drive wheels toeffect propulsion of the deck over the ground. A control system isprovided and includes a handle grip positioned at or near the upper endof, and translatable along, the handle member. Translation of the handlegrip activates the transmission to power at least one of the drivewheels for movement of the deck: in the forward direction when thehandle grip is translated downwardly along the handle member from aneutral position; and in the reverse direction when the handle grip istranslated upwardly along the handle member from the neutral position.

In still yet another aspect of the present disclosure, a walk powermower is provided that includes a deck supported upon the ground byfront wheels and rear wheels, the deck adapted to traverse the ground inboth a forward direction and an opposite, reverse direction, wherein oneor more of the front wheels and the rear wheels operate as a powereddrive wheel of the mower. The mower also includes a handle having ahandle member extending upwardly and rearwardly from the deck, whereinthe handle member has: an upper end comprising a grip area; and a lowerend attached to the deck. A prime mover is also provided and carried bythe deck, the prime mover being operatively connected to a cuttingmember. A variable speed, bidirectional traction drive system is alsocarried by the deck, wherein the traction drive system selectivelyrotates the drive wheel to effect propulsion of the deck over theground. A control system is carried on the handle and operativelyconnected to the traction drive system, wherein the control systemcomprises a first control member and a second control member that areeach independently movable between a neutral position corresponding to aneutral mode of the traction drive system, and a fully engaged positioncorresponding to a powered mode of the traction drive system. The firstcontrol member, when moved from the neutral position to the engagedposition, is adapted to manipulate the traction drive system from: theneutral mode; to a forward powered mode wherein the traction drivesystem rotates the drive wheel in a first direction corresponding to theforward direction of the deck. Similarly, the second control member,when moved from the neutral position to the engaged position, is adaptedto manipulate the traction drive system from: the neutral mode; to areverse powered mode wherein the traction drive system rotates the drivewheel in a second direction corresponding to the reverse direction ofthe deck.

In yet another aspect, the present disclosure relates to a walk powermower including: a grass cutting deck surrounding a grass cuttingmember, wherein the cutting deck is adapted to travel over the ground inboth a forward direction and a reverse direction; and a handlecomprising an upwardly and rearwardly extending handle member. Thehandle member includes an upper end comprising a grip area, and a lowerend pivotally attached to the cutting deck such that the handle memberpivots about a transverse pivot axis within an operating range ofpivotal motion defined by: an upper stop corresponding to the handlebeing in a first operating orientation; and a lower stop correspondingto the handle being in a second operating orientation, the operatingrange of pivotal motion being at least about 5 degrees. A resilientmember is operatively positioned between the lower stop and the handlemember, wherein the resilient member is adapted to bias the handlemember to a location at or near the upper stop.

In still another aspect, the present disclosure relates to a walk powermower comprising: a grass cutting deck supported upon the ground by afront wheel and a rear wheel, the cutting deck surrounding a grasscutting member, wherein the cutting deck is adapted to traverse theground in both a forward direction and a reverse direction; at least onetransmission adapted to selectively provide driving power to at leastone wheel of the front and rear wheels; and a handle comprising firstand second laterally spaced-apart and parallel handle members eachextending upwardly and rearwardly from the cutting deck. The first andsecond handle members each comprise: an upper end; and a lower endpivotally attached to the cutting deck such that the handle memberspivot about a transverse pivot axis within an operating range of pivotalmotion defined by: an upper stop corresponding to the handle being in afirst operating orientation; and a lower stop corresponding to thehandle being in a second operating orientation, the operating range ofpivotal motion being about 5-20 degrees. A control member is carried ator near the upper ends of the first and second handle members, whereinthe control member, when moved to a first engaged position, is adaptedto place the transmission into operation so that the transmissionpropels the mower in the forward direction. First and second resilientmembers are provided and positioned between the deck and the first andsecond handle members, respectively, the first and second resilientmembers adapted to bias the first and second handle members to alocation at or near the upper stop.

In still yet another aspect, a walk power mower is provided thatincludes: a grass cutting deck supported upon the ground by a pair offront wheels and a pair of rear wheels, the cutting deck surrounding atleast one grass cutting blade; and a variable speed traction drivesystem carried on the cutting deck and adapted to selectively providedriving power to at least one wheel of the front and rear pairs ofwheels to propel the mower over the ground in both a forward directionand a reverse direction. A handle is also provided and includes firstand second laterally spaced-apart and parallel handle members extendingupwardly and rearwardly from the cutting deck, wherein the first andsecond handle members each comprise: an upper end; and a lower endpivotally attached to a rear portion of the cutting deck such that thehandle members pivot about a transverse pivot axis within an operatingrange of pivotal motion defined by an upper stop and a lower stop. Themower also includes a control system carried at or near the upper endsof the first and second handle members, the control system operable toengage the traction drive system to selectively propel the cutting deckin both the forward direction and the reverse direction. First andsecond resilient members are provided and positioned between the deckand the first and second handle members, respectively. The first andsecond resilient members are adapted to resiliently deform when thehandle members pivot, about the transverse pivot axis, from a positionat or near the upper stop toward a position at or near the lower stop.

Yet another aspect of this disclosure relates to a walk power mowerwhich comprises a deck supported by a pair of front wheels and a pair ofrear wheels. The deck has at least one grass cutting blade that rotatesin a substantially horizontal plane about a substantially vertical axisto cut grass. The deck also has an upwardly and rearwardly extendinghandle that is gripped by a user who walks on the ground behind the deckto guide and manipulate the deck during motion of the deck over theground. A prime mover is carried by the deck, the prime mover beingoperably coupled to the blade for effecting powered rotation of theblade. A variable speed traction drive system is carried on the deck,the prime mover being operably coupled to the traction drive system foreffecting powered rotation of the front wheels and the rear wheels. Thetraction drive system comprises a rear transmission having a rear axlethat is operatively connected to the rear wheels for powering the rearwheels to provide self-propelled motion of the deck in a first directionof motion over the ground, a front transmission having a front axle thatis operatively connected to the front wheels for powering the frontwheels to provide self-propelled motion of the deck in a seconddirection of motion over the ground that is opposite to the firstdirection of motion, and a control system carried on the handle that isselectively operable by a user for placing only one transmission at atime into operation so that the rear transmission is active to propelthe deck in the first direction while the front transmission is inactiveor the front transmission is active to propel the deck in the seconddirection while the rear transmission is inactive.

Yet another aspect of this disclosure relates to a walk power mowerwhich comprises a traction drive system on a grass cutting deck having apair of front wheels and a pair of rear wheels. A pair of transmissionspower at least one pair of wheels on the deck. A first one of thetransmissions provides forward motion of the mower when it is active anda second one of the transmissions provides rearward motion of the mowerwhen it is active. A slidable handle grip is provided on a handleextending upwardly and rearwardly from the cutting deck. The handle griphas a cross bar long enough to be gripped by both hands of the user. Thehandle grip activates the first one of the transmissions when it is sliddownwardly on a handle out of a neutral position thereof as a user walksforwardly holding the cross bar of the handle grip. The handle gripactivates the second one of the transmissions when it is slid upwardlyon the handle out of the neutral position as a user walks rearwardlyholding the cross bar of the handle grip.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of this disclosure will be described more fully in thefollowing Detailed Description, when taken in conjunction with thefollowing drawings, in which like reference numerals refer to likeelements throughout.

FIG. 1 is a perspective view of one embodiment of a walk power moweraccording to this disclosure;

FIG. 2 is an enlarged perspective view of a portion of the handle of themower of FIG. 1 , particularly illustrating the return to neutral systemthat causes the slidable handle grip of the handle to return to aneutral position in which the traction drive system is disengaged oncethe user releases the handle grip;

FIG. 3 is a perspective view of the underside of the cutting deck of themower of FIG. 1 , particularly illustrating a dual transmission tractiondrive system;

FIG. 4 is a perspective view of a portion of a second embodiment of awalk power mower according to this disclosure;

FIG. 5 is an enlarged perspective view of a portion of the handle of themower of FIG. 4 , particularly illustrating a second embodiment of thereturn to neutral system that causes the slidable handle grip of thehandle to return to a neutral position in which the traction drivesystem is disengaged once the user releases the handle grip;

FIG. 6 is a perspective view of the underside of a mower cutting deck inaccordance with another embodiment of this disclosure, the mower shownwith a bidirectional, single (forward and reverse) transmission tractiondrive system;

FIGS. 7A-7C illustrate various embodiments of a traction drive system inaccordance with embodiments of the present disclosure, wherein: FIG. 7Ais a diagrammatic view of a bidirectional transmission powered by a beltconnected to a prime mover of the mower;

FIG. 7B is a diagrammatic view of a bidirectional transmission poweredby an independent motor separate from the mower's prime mover; and FIG.7C is a diagrammatic view of a bidirectional transmission(s) attached toa drive wheel of the mower, wherein each transmission is configured asan electric motor;

FIG. 8 is a perspective view of a portion of an exemplary handle for usewith the mower of FIG. 6 , the handle including a forward bail and aseparate reverse bail;

FIG. 9 is a perspective view of a mower in accordance with anotherembodiment of the present disclosure, the mower including casteringfront wheels;

FIGS. 10A-10B illustrate a mower in accordance with another embodimentof this disclosure, the mower incorporating a biased or “floating”handle, wherein: FIG. 10A is a rear perspective view; and FIG. 10B is afront perspective view;

FIG. 11 is an enlarged view of a portion of the mower of FIGS. 10A-10B;

FIG. 12 is an exploded perspective view of a portion of the mower ofFIGS. 10A-10B;

FIG. 13 is a perspective view of a resilient member for use with themower of FIGS. 10A-10B; and

FIG. 14 is a side elevation view of the mower of FIGS. 10A-10B.

The figures are rendered primarily for clarity and, as a result, are notnecessarily drawn to scale. Moreover, various structure/components,including but not limited to fasteners, electrical components (wiring,cables, etc.), and the like, may be shown diagrammatically or removedfrom some or all of the views to better illustrate aspects of thedepicted embodiments, or where inclusion of such structure/components isnot necessary to an understanding of the various exemplary embodimentsdescribed herein. The lack of illustration/description of suchstructure/components in a particular figure is, however, not to beinterpreted as limiting the scope of the various embodiments in any way.Still further, “Figure x” and “FIG. x” may be used interchangeablyherein to refer to the figure numbered “x.”

DETAILED DESCRIPTION

One embodiment of a walk power mower 2 according to this disclosure isillustrated in FIG. 1 . Mower 2 comprises a housing or cutting deck 4that is formed with a generally toroidal cutting chamber 6 that facesdownwardly and is open at its bottom. Deck 4 is supported for rollingover the ground by a pair of front wheels 8 and a pair of rear wheels10. A prime mover 12, such as an internal combustion engine, is carriedon top of deck 4. Referring now to FIG. 3 , the drive shaft 14 of theprime mover extends vertically downwardly with its lower end extendinginto cutting chamber 6. A horizontal cutting member or blade 16 ispositioned within cutting chamber 6 and is removably secured to thelower end of drive shaft 14 to rotate in a generally horizontal cuttingplane to cut grass.

Referring again to FIG. 1 , mower 2 is a three-in-one mower having sidedischarge, rear bagging and mulching modes of operation. In the sidedischarge mode, a side discharge chute 18 can be mated with a sidedischarge opening to discharge grass clippings to the side of mower 2when a side discharge door 20 is opened. In the rear bagging mode, agrass clipping collection bag 22 is mated with a rear discharge openingto collect grass clippings being discharged to the rear of mower 2 whena rear discharge door 24 is opened. While FIG. 1 illustrates deck 4 asbeing both in the side discharge mode and the rear bagging mode, this isonly for the purpose of illustration as these two modes would not beused simultaneously. When side discharge chute 18 is removed and sidedischarge door 20 is closed and when bag 22 is removed and reardischarge door 24 is closed, mower 2 is placed into its mulching mode inwhich grass clippings are driven downwardly out of cutting chamber 6 todischarge the clippings beneath mower 2. However, mower 2 need not havemultiple modes of operation, but could be built as a single purpose sidedischarge, rear bagger, or mulching mower.

An upwardly and rearwardly extending handle 26 comprising a pair oflaterally spaced handle members or tubes 28 joined by a top cross member30. The lower ends of handle tubes 28 are attached to the rear of deck4. Handle 26 includes a U-shaped handle grip 32 that has a pair oflaterally spaced legs 34 connected together by an upper cross bar 36.Legs 34 of handle grip 32 are telescopically received on handle tubes 28of handle 26 for sliding movement relative thereto. Thus, handle grip 32is able to slide downwardly (translate along) on handle tubes 28 as auser walks forwardly while gripping cross bar 36 of handle grip 32 withboth of the user's hands.

Handle grip 32 slides downwardly by an amount that depends upon how fastthe user walks forwardly. As will be described in more detail hereafter,the extent or amount of downward travel of handle grip 32 controls atraction drive system 38 (see FIG. 3 ) of mower 2 to vary the forwardground speed of mower 2 to correspond to the user's walking pace. Thistype of speed controlling, slidable handle grip is used on the PersonalPace® line of walk power mowers manufactured and sold by The ToroCompany, the assignee herein. In addition, this type of slidable handlegrip is disclosed more fully in U.S. Pat. No. 6,082,083 to Stalpes etal., which patent is hereby incorporated by reference and shall bereferred to as “Stalpes” hereafter.

In Stalpes, handle grip 32 is in a neutral, i.e., a drive disengagedposition, when handle grip 32 is at the top of handle 26 with handlegrip 32 located adjacent to cross member 30 that joins handle tubes 28together. The only control motion of handle grip 32 in Stalpes is thedownward sliding motion that engages the traction drive system ofStalpes in forward and that varies the forward ground speed in concertwith the user's forward walking pace. When the user lets go of handlegrip 32 in Stalpes, handle grip 32 is spring biased to slide back uphandle 26 to return to the top thereof at which point the traction drivesystem becomes disengaged once again.

In mower 2 of this disclosure, the Stalpes handle grip 32 has beenmodified so that the neutral position of handle grip 32 is no longer atthe top of the range of motion of handle grip 32. Now, the neutralposition of handle grip 32 is displaced somewhat downwardly from crossmember 30 of handle 26. A return to neutral system 40 maintains handlegrip 32 in its now lower neutral position relative to cross member 30 ofhandle 26.

Handle grip 32 functions as it did in Stalpes when the user grips crossbar 36 of handle grip 32 and walks forwardly, i.e., handle grip 32slides downwardly in the direction of the arrow A in FIG. 1 to activatetraction drive system 38 in forward and to vary the forward ground speedin concert with the user's forward walking pace. Now, however, if theuser grips cross bar 36 of handle grip 32 and walks rearwardly, as whenpulling mower 2 back, handle grip 32 is now also able to slide upwardlyout of neutral rather than being held in neutral as in Stalpes. Thisupward sliding motion of handle grip 32 is shown by the arrow B in FIG.1 . This activates traction drive system 38 in reverse and varies thereverse ground speed of mower 2 in concert with the user's rearwardwalking pace. In either forward or reverse powered motion of mower 2,when the user lets go of handle grip 32, return to neutral system 40causes handle grip 32 to slide back to its centered neutral positionbetween the lower and upper limits of the range of motion of handle grip32 to disengage traction drive system 38.

Referring now to FIG. 2 , return to neutral system 40 comprises a rod 42having an upper end fixed by a bracket 44 to a laterally extending crossmember 46 that is also part of handle grip 32. Rod 42 has spaced upperand lower push nuts 48 _(u) and 48 _(l) fixed thereto to move with rod42. Push nuts 48 bear respectively against one end of cylindrical, upperand lower, push tubes 50 _(u) and 50 _(l) which are spaced along thelength of rod 42 and through which rod 42 slides. Each push tube 50 hasan annular thrust surface 52 that is formed as an integral part thereof.Push tubes 50 are assembled in an inverted relationship relative to eachother along the length of rod 42 such that thrust surface 52 of upperpush tube 50 _(u) is at the lowermost end of upper push tube 50 _(u)while thrust surface 52 of lower push tube 50 _(l) is at the uppermostend of lower push tube 50 _(l).

Return to neutral system 40 further includes a U-shaped clevis 54 fixedto handle 26 with the spaced, parallel side walls 56 of clevis 54forming an upper wall 56 _(u) and a lower wall 56 _(l). Upper and lowerpush tubes 50 _(u) and 50 _(l) when assembled on rod 42 are arranged topass through bores in upper and lower walls 56 _(u) and 56 _(l) ofclevis 54 with thrust surfaces 52 on upper and lower push tubes 50 _(u)and 50 _(l) being inside clevis 54 immediately adjacent to upper andlower walls 56 _(u) and 56 _(l) of clevis 54. A compression spring 58 isarranged inside clevis 54 with the ends of spring 58 bearing againstthrust surfaces 52 of upper and lower push tubes 50 _(u) and 50 _(l).When return to neutral system 40 is properly adjusted and traction drivesystem 38 is in neutral, spring 58 will force upper and lower push tubes50 _(u) and 50 _(l) apart until thrust surfaces 52 thereon abut againstthe upper and lower walls 56 _(u) and 56 _(l) of clevis 54 and theopposite ends of upper and lower push tubes 50 _(u) and 50 _(l) areimmediately adjacent to upper and lower push nuts 48 _(u) and 48 _(l).

When the user pushes down on handle grip 32 to initiate powered forwardmotion of mower 2, upper push nut 48 _(u) on rod 42 presses down on theupper end of upper push tube 50 _(u) to slide upper push tube 50 _(u)downwardly relative to clevis 54. Note that lower push tube 50 _(l)remains stationary with rod 42 simply sliding through lower push tube 50_(l) since the lower push nut 48 _(l) moves away from the lowermost endof lower push tube 50 _(l) and lower push tube 50 _(l) remains withinclevis 54 since thrust surface 52 on lower push tube 50 _(l) is held inplace by its engagement with lower wall 56 _(l) of clevis 54. Thedownward motion of upper push tube 50 _(u) compresses spring 58downwardly. Thus, when the user eventually releases handle grip 32, thecompressed spring 58 pushes back upwardly on upper push tube 50 _(u) tocause the uppermost end of upper push tube 50 _(u) to push the upperpush nut 48 _(u) back upwardly, thereby returning handle grip 32 to itscentered neutral position.

Return to neutral system 40 works the same way but in an oppositefashion when handle grip 32 is pulled upwardly in the direction of thearrow B to initiate reverse powered motion of mower 2. This time it islower push tube 50 _(l) that is pushed upwardly by lower push nut 48_(l) with upper push tube 50 _(u) remaining stationary. Thus, spring 58is compressed upwardly. When handle grip 32 is eventually released, thelowermost end of lower push tube 50 _(l) pushes downwardly on lower pushnut 48 _(l) as the upward compression of spring 58 is released to slidehandle grip 32 back downwardly to return handle grip 32 to its centeredneutral position.

Referring now to FIG. 3 , traction drive system 38 comprises a firstrear transmission 60 _(r) which powers rear wheels 10 of mower 2 and asecond front transmission 60 _(f) which powers front wheels 8 of mower2. Transmissions 60 preferably comprise, but are not limited to,mechanical gear drive transmissions that use various speed reductionstages to reduce the relatively high rotational speed of drive shaft 14of prime mover 12 to a lower speed suitable for self-propelling mower 2at ground speeds that match the walking pace of the user. Some of thesespeed reduction stages are built into the gearing inside the housings oftransmissions 60. However, the final speed reduction stage is formed bya small diameter drive gear 62 on each end of an axle 64 of eachtransmission 60 that drives a larger diameter driven gear 66 fixedlyattached to one of wheels 8, 10.

Drive gears 62 on the opposite ends of axle 64 of rear transmission 60_(r) engage the backsides of driven gears 66 of rear wheels 10. Thereverse is true for drive gears 62 for front transmission 60 _(f) whichengage the front sides of driven gears 66 of front wheels 8. Thus, whenaxles 64 of transmissions 60 are rotated in opposite directions by theoperation of prime mover 12, front and rear drive wheels 8 and 10 willbe rotated in opposite directions relative to each other. For example,if rear drive wheels 10 are rotated in a forward direction to propelmower 2 forwardly, front drive wheels 8 will be rotated in a rearwarddirection to propel mower 2 in reverse. As a consequence, it should beapparent that only one transmission 60 is active at any given time whilethe other transmission 60 remains inactive. Either transmission 60 canbe selected to be the one that provides forward motion while theremaining transmission 60 will then be the one that provides reversemotion.

Rear transmission 60 preferably has a split axle 64 and provides adifferential action to permit rear wheels 10 to be driven at differentspeeds during a turn, such as when the user swings mower 2 around 180°at the end of a pass when mowing his or her lawn, to avoid tearing orscuffing the grass. Rear wheels 10 may rotate at different speeds duringturns using either an unpowered or powered differential. For example, inan unpowered differential which is preferred due to somewhat lower cost,the portion of split axle 64 powering whichever rear wheel 10 is on theoutside of the turn simply overruns the rotational speed of the portionof split axle 64 powering the rear wheel 10 on the inside of the turn tocreate the difference in wheel speed. Since front wheels 8 of mower 2are typically lifted up off the ground during such a turnaround of mower2, front transmission 60 preferably has a solid axle and lacks anydifferential action, thereby reducing overall cost of mower 2.

Each transmission 60 is provided with a one-way clutch that permits thewheels driven by that transmission 60 to free wheel when mower 2 isbeing propelled in a direction opposite to the direction transmission 60is designed to operate. In the example where one transmission is activeand is driving mower 2 forwardly while the other reverse drivetransmission is inactive and is not in operation, the one-way clutch inthe inactive reverse drive transmission permits the drive wheels coupledto that transmission to rotate freely with respect to the internalgearing of the reverse drive transmission to avoid the drag orresistance such internal gearing would otherwise provide when mower 2moves forwardly.

Each front and rear transmission 60 _(f) and 60 _(r) is separatelydriven by its own independent belt drive 68 _(f) and 68 _(r) from driveshaft 14 of prime mover 12. Each transmission 60 is a rockingtransmission of the type disclosed in Stalpes. When handle grip 32 is inneutral and both transmissions 60 are inactive, belts 70 in belt drives68 are sufficiently slack so that the input pulleys on transmissions 60are stationary even though drive shaft 14 of prime mover 12 is rotating.Effectively, mower 2 is at rest even with the engine running when handlegrip 32 is not being pushed or pulled by the user.

However, as the user slides handle grip 32 up or down on handle 26 ineither the downward direction A or the upward direction B, this motionrocks one transmission 60 in a direction (rearwardly about its axle 64for rear transmission 60 _(r) and forwardly about its axle 64 for fronttransmission 60 _(f)) to tighten drive belt 70 to the rockingtransmission while leaving drive belt 70 to other transmission slack. Asdrive belt 70 to the rocking transmission becomes taut, the transmissionbecomes active to begin rotating the pair of wheels powered by therocking transmission. The speed of rotation of axle 64 of the rockingtransmission, and thus the ground speed of mower 2, progressivelyincreases as handle grip 32 is moved ever further in the selecteddirection and the tautness of belt 70 progressively increases. Thus, theground speed of mower 2 progressively increases from zero to a maximumspeed as handle grip 32 travels out of neutral to the end of its rangeof motion in the selected direction A or B. This enables the groundspeed of mower 2 to be matched to the walking pace of the user whethermower 2 is being propelled in forward or reverse.

First and second Bowden cables (not shown) having inner wires carriedwithin outer conduits operably couple handle grip 32 to transmissions60. The first Bowden cable has a “live cable” setup in which a rear endof the outer conduit is fixed or clamped to handle 26 and the front endof the outer conduit is fixed or clamped to a lower end of one handletube 28 or to a rear end of deck 4. The rear end of the inner wire ofthe first Bowden cable is secured to an opening 72 in a pivotal tab 74(see FIG. 2 ) that is rotated rearwardly when handle grip 32 is moveddownwardly in the direction of arrow A. The front end of the inner wireof the first Bowden cable is then attached to rear transmission 60 _(r)to rock rear transmission 60 _(r) rearwardly during downward motion ofhandle grip 32 in the direction of arrow A. In this “live cable” setupof the first Bowden cable, the downward motion of handle grip 32 causesthe “live” inner wire of the first Bowden cable to slide rearwardlywithin the outer conduit in order to rock rear transmission 60 _(r)rearwardly while the outer conduit remains fixed in place. The “livecable” setup of the first Bowden cable and its interaction with pivotaltab 74 is shown and described in more detail in the Stalpes patent whichhas previously been incorporated by reference herein.

The second Bowden cable has a “live conduit” setup in which the frontend of the inner wire is fixed or clamped in place to deck 4 and therear end of the inner wire is fixed or clamped in place to handle grip32. The rear end of the conduit in the second Bowden cable is fixed orclamped in place to an upper portion of one handle tube 28 adjacent theplace where the rear end of the inner wire of the second Bowden cableattaches to handle grip 32. The front end of the conduit in the secondBowden cable is clamped or fixed to front transmission 60 to rock fronttransmission 60 forwardly during upward motion of handle grip 32 in thedirection of arrow B. In this “live conduit” setup, the upward motion ofhandle grip 32 in the direction of arrow B deforms the shape of theclamped inner wire of the second Bowden cable. This deformation in theshape of the inner wire causes the “live” conduit of the second Bowdencable to slide forwardly over the inner wire to push against fronttransmission 60 _(f) to rock front transmission 60 _(f) forwardly. Onlyone Bowden cable applies force to only one transmission at any giventime with the other Bowden cable not applying force to the othertransmission so that only one transmission at a time is activated.

Mower 2 equipped with traction drive system 38 of this disclosure haspowered operation of rear transmission 60 _(r) to propel mower 2forwardly in a variable speed manner as handle grip 32 is gripped by theuser and the user walks forwardly, thereby sliding handle grip 32downwardly on handle 26 in an amount proportional to the walking pace ofthe user. However, when trying to pull mower 2 back during a trimmingoperation or when trying to mow a small patch of grass in reverse, theuser no longer has to use manual force to manhandle mower 2 in thereverse direction. Instead, the user merely maintains his or her grip oncross bar 36 of handle grip 32 and walks rearwardly at any desired pace.This will slide handle grip 32 upwardly on handle 26 to initiate poweredoperation of front transmission 60 to propel mower 2 rearwardly at avariable ground speed commensurate to the walking pace of the user.Thus, the task of operating mower 2 is greatly eased since mower 2 isself-propelled both in forward and reverse while maintaining thefunctionality of the Personal Pace® control system of The Toro Companythat had previously been used only on mowers that were self-propelled inforward only.

The advantages of a mower that is self-propelled in both forward andreverse is achieved in a cost-effective manner by using mechanical, geardrive transmissions that are both durable and inexpensive in comparisonto using hydraulic motor/pump combinations or electric motor/drivecombinations. Moreover, since transmissions 60 used to drive front andrear wheels 8, 10 are different from one another and are mounted onseparate front and rear axles, this allows rear transmission 60 _(r) tohave a split axle/differential action configuration while fronttransmission 60 _(f) has a solid axle/non-differential actionconfiguration. The manner of driving front and rear wheels 8, 10 usingthe same size drive gears 62 on the ends of the axles of the front andrear transmissions and the same size driven gears 66 on the wheels, butsimply reversing which sides of driven gears 66 are engaged by drivegears 62, leads to increased part commonality and thus reduced cost.This allows a powered, reversible mower to be manufactured and sold at areasonable cost.

Referring now to FIGS. 4 and 5 , a second embodiment of a moweraccording to this disclosure is illustrated generally as 2′. The samereference numerals used in FIGS. 1-3 to refer to components will be usedin FIGS. 4 and 5 to refer to the same or corresponding components with aprime designation being used to refer to those components in the secondembodiment, e.g. mower 2′ in FIGS. 4 and 5 as opposed to mower 2 inFIGS. 1-3 .

Referring now to FIG. 4 , in mower 2′ front transmission 60 _(f)′ andits axle 64′ have been relocated from the front to the back of mower 2′so that only rear wheels 10′ are reversibly driven by the dualtransmissions 60 _(f)′ and 60 _(r)′ with such transmissions and theiraxles being disposed on opposite sides of the axis of rotation of rearwheels 10′. In this embodiment, front wheels 8′ are present butunpowered with only rear wheels 10′ serving to self-propel mower 2′. Asin the first embodiment concerning mower 2, only one transmission 60′(driven by belt 70′ and having a drive gear 62′ engaged with driven gear66′) is active at any given time while the other transmission 60′(driven by another belt 70′ and also having a drive gear 62′ engagedwith driven gear 66′) remains inactive. Propelling rear wheels 10′ inopposite directions may yield better traction than using front wheels 8′to drive mower 2′ in the direction that is opposite to the directionthat rear wheels 10′ drive mower 2′. This is due to the fact that moreof the weight of a mower like mower 2, 2′ is over rear wheels 10′ ascompared to front wheels 8′. In addition, the filling of a grassclipping collection bag at the rear of mower 2′ with grass clippingsduring a mowing operation only accentuates this rearward weightdistribution.

In mower 2′ as shown in FIG. 4 , whichever transmission 60′ is used toproduce forward motion of mower 2′ is preferably one having a splitaxle/differential feature as described earlier with respect to reartransmission 60 _(r) in mower 2. The other transmission 60′ that is usedto produce reverse motion of mower 2′ could also be one having a splitaxle/differential feature since both transmissions are now being used topower rear wheels 10′. However, since the times at which reverse motionis needed and the distances over which mower 2′ would travel in reverseare much more limited than what is required for forward motion,whichever transmission 60′ propels the mower in reverse could remain atransmission having a solid axle without any differential ability.

In addition to the use of both transmissions 60′ to drive rear wheels10′, a simplified Bowden cable coupling setup is used in mower 2′ asshown in FIG. 5 . In mower 2′, pivotal tab 74′ now has a second opening76 that is disposed on an opposite side of a horizontal axis ofrotation, illustrated as x in FIG. 5 , of a pivot rod 78 compared to thelocation of first opening 72′ in tab 74′. As taught in more detail inStalpes, tab 74′ is rigidly attached to rod 78 to pivot by virtue of thepivoting motion of rod 78 caused by journaling the ends of rod 78 in themower handle tubes 28′ while a middle U-shaped portion 79 of rod 78 iscaptured within a channel 80 in cross member 46′ of slidable handle grip32′. Again, rod 78 and its interaction with cross member 46′ aredetailed more fully in the Stalpes patent which has been incorporated byreference herein.

When the user slides handle grip 32′ downwardly on handle tubes 28′, theportion of tab 74′ having opening 72′ is pivoted rearwardly as describedin connection with the operation of mower 2. This pulls rearwardly onthe “live cable” setup of the first Bowden cable that is connected towhichever transmission 60′ is arranged to drive mower 2′ forwardly toactuate the forward drive transmission 60′. Whichever transmission 60′is arranged to drive mower 2′ in reverse is now connected by a “livecable” setup of the second Bowden cable to the newly added secondopening 76 in tab 74′. Thus, when the user pulls handle grip 32′upwardly on handle tubes 28′ as he or she walks in reverse, the portionof tab 74′ having opening 76 is now pivoted rearwardly to actuate thereverse drive transmission 60′. Since both transmissions 60′ are now atthe rear of mower 2′, the length of the second Bowden cable run isshortened compared to the length required in mower 2, and a “live cable”rather than a “live conduit” setup of the Bowden cable is used. Thissimplifies the routing and arrangement of the Bowden cables. However,the operation of mower 2′ is the same as mower 2, namely pushing handlegrip 32′ downwardly as the user walks forwardly powers mower 2′ in aforward direction at a speed commensurate to the user's walking pacewhile pulling handle grip 32′ upwardly as the user walks rearwardlypowers mower 2′ in a rearward direction at a speed commensurate to theuser's walking pace.

Referring still further to FIG. 5 , the use of the double headed tab 74′as described above to activate both transmission 60 _(f′) and 60 _(r)′in mower 2′ permits a simplified return to neutral system 40′. All thatis required now is the use of one or more torsion springs 82, preferablytwo such springs 82, surrounding the ends of rod 78 that lie along anddefine the rotational axis x of rod 78 with such springs being anchoredat one end on rod 78 and at the other end on a portion of the adjacenthandle tube 28′. When handle grip 32′ is located in its centered,neutral, drive disengaging position, torsion springs 82 are in theirunstressed state such that handle grip 32′ is retained in neutral. Asrod 78 is rotated about axis x in either one direction or the other dueto motion of handle grip 32′ relative to handle tubes 28′, torsionsprings 82 get coiled up or twisted in one direction or the other toresist the motion of handle grip 32′ out of neutral. When the usersubsequently releases handle grip 32′, the biasing force built up in thecoiled torsion springs 82 is now free to act on handle grip 32′ to moveit back to neutral.

The return to neutral system 40′ as shown in FIG. 5 is simpler and thusless costly than system 40 shown in FIGS. 1-3 and takes up less space onmower 2′. Thus, the cable coupling setup and return to neutral system40′ shown in FIG. 5 could be used with mower 2 shown in FIGS. 1-3 if sodesired.

While traction drive systems are shown in FIGS. 1-5 as utilizingdiscrete forward and reverse transmissions, such a construction isexemplary only as other traction drive systems are contemplated. Forexample, FIG. 6 illustrate a power equipment unit (e.g., self-propelled,walk power mower 300) that utilizes a traction drive system having asingle, variable speed, bidirectional transmission 360 carried by thedeck that alternatively powers one or more drive wheels (e.g., two rearwheels 310) to selectively propel the deck over the ground in bothforward and reverse directions. While shown as being used to power therear wheels 310, the mower 300 could, in addition or alternatively,include a bidirectional transmission (see broken line rendering of fronttransmission 360 in FIG. 6 ) powering the two front wheels 308. In stillother embodiments, only one of the front and rear transmissions may bebidirectional, while the other transmission provides driving power inonly a single (e.g., forward) direction. Other aspects of the mower 300may be similar to the mower 2 (or 2′) already described herein (e.g.,the mower 300 may include the deck 4, engine 12 (see FIG. 1 ), blade 16,and handle (not shown, but see handles described elsewhere herein).Accordingly, further description of these features of the mower 300 isnot provided herein.

Utilizing a power equipment unit incorporating a singular, bidirectionaltransmission 360 may provide various benefits over dual transmissionconfigurations including, for example, reduced cost and weight.Moreover, a single transmission may also benefit from a comparativelysimplified control system. For example, cables (e.g., such as the Bowdencables described above connecting the handle grip 32/32′ to thetransmissions) may require connection to only a single transmission,thereby simplifying cable routing/adjustment.

FIG. 7A diagrammatically represents a forward/reverse transmission 360in accordance with one embodiment of this disclosure. While illustratedwith some specificity, the transmission 360 illustrated in FIG. 7A isexemplary only as other bidirectional transmissions are certainlycontemplated within the scope of this disclosure.

The transmission 360 may be carried by the deck 4 and may include aninput sheave 362 powered by a belt 70 (belt is not illustrated in FIG. 6as it is beneath cover 71, but see FIG. 3 ) connected to the drive shaft(see 14 in FIG. 3 ). The sheave 362 is fixed to a journaled shaft 364having a bevel gear 366 such that, when the sheave 362 rotates, thebevel gear 366 rotates in the same direction.

The bevel gear 366 meshes with first (forward) and second (reverse)bevel gears 368, 370, which are each journaled for rotation about anaxis 305 perpendicular to an axis of the shaft 364. As a result, whenthe input sheave 362 rotates, the first and second bevel gears 368, 370also rotate about their axis 305, albeit in opposite directions.

A cone gear 372 may be located between the first and second bevel gears368, 370. The cone gear may be selectively translatable between: contactwith the first bevel gear 368; and contact with the second bevel gear370. The cone gear 372 may include friction surfaces 374 on each side,the friction surfaces adapted to alternatively engage associatedfriction surfaces 376 of the first and second bevel gears. Morespecifically, when the cone gear 372 is displaced to the right in FIG.7A such that its right-side friction surfaces 374 engage the frictionsurfaces 376 of the first bevel gear 368, the cone gear will rotate in afirst direction ultimately corresponding to propulsion of the mower inthe forward direction. Similarly, displacement of the cone gear to theleft in FIG. 7A such that its left-side friction surfaces 374 engage thefriction surfaces 376 of the second bevel gear 370 will cause the conegear to rotate in a second opposite direction ultimately correspondingto propulsion of the mower in the opposite, reverse direction.

The cone gear 372 includes gear teeth that mesh with an axle gear 378operatively connected to the drive wheel axle 364. As already describedabove, the axle 364 may include a differential 380 (diagrammaticallyillustrated) that allows each drive wheel to rotate independent of theother, i.e., during turns. While shown as incorporating the differential380, other embodiments may use a solid axle without departing from thescope of this disclosure.

The cone gear 373 may be connected, via Bowden cables 382, 384 to themower's control system. For example, with the control system shown inFIG. 5 , the cable 382 may be connected between the cone gear 372 andthe opening 72′, while the cable 384 may be connected between the conegear and the opening 76. As a result, when the operator moves the handle36′ (see FIG. 5 ) downwardly, the tab 74′ may pivot such that theopening 72′ moves rearwardly, displacing the cable 382 and causing thecone gear 372 to slide to the right in FIG. 7A. As the friction surfaces374 of the cone gear engage the friction surfaces 376 of the first bevelgear 368, the cone gear will rotate in the first direction, causing themower to be propelled in the forward direction.

Similarly, when the operator moves the handle 36′ upwardly in FIG. 5 ,the tab 74′ may pivot such that the opening 76 moves rearwardly,displacing the cable 384 and causing the cone gear 372 to slide to theleft in FIG. 7A. As the friction surfaces 374 of the cone gear engagethe friction surfaces 376 of the second bevel gear 370, the cone gearwill rotate in the second direction, causing the mower to be propelledin the reverse direction.

Engagement of the cone gear 372 with either of the bevel gears 368, 370may be proportional to the movement of the handle 36′. Accordingly, thespeed of mower propulsion may be associated with the degree of movementof the handle 36′. That is to say, the speed of the mower 300 (in bothforward and reverse directions) may be dependent upon how much force theoperator applies to the handle 36′.

The forward/reverse transmission 360 shown in FIG. 7A may be powered,via belt 70, by the mower's prime mover 12 (see, e.g., FIG. 1 ), thelatter of which may be an internal combustion engine, an electric motor,or another power source. That is to say, the transmission 360 may bepowered by the same power source used to rotate the cutting member 16(see, e.g., FIG. 6 ).

However, such a configuration is not limiting. For example, FIG. 7Billustrates a bidirectional transmission 1360 that is similar in manyrespects to the transmission 360 described above. Instead of receivingpower from the prime mover 12, however, the transmission 1360 includesan independent propulsion motor 1362 connected to or integral with thetransmission to provide power to the same. For instance, the motor 1362may be an electric motor that is powered by an onboard battery system1364 that may also provide power to the prime mover 12 (assuming thelatter is configured as an electric motor). While the actualconstruction of the battery system 1364 may vary, it may in someembodiments include one or more lithium-based battery cells as is knownin the art. Alternatively, the motor 1362 and prime mover 12 could bepowered by separate and independent battery systems. Still further, oneor both of the motor 1362 and prime mover 12 could receive AC power froman external power source.

In yet another potential drive system, the transmission may beconfigured as one or more, e.g., two, independent electric motors 1462directly coupled to the mower drive wheels (e.g., one to each of therear wheels 310) as shown in FIG. 7C. As with the motor 1362, the motors1462 may be powered by a battery system 1364 that is either dedicated tomower propulsion, or is shared with the prime mover 12 (not shown inFIG. 7C). Each electric motor 1462 and 1362 may, as is known in the art,be reversible to provide the desired forward/reverse propulsion.

One benefit of the electric transmissions 1360, 1462 is that nomechanical interconnection is required between the handle and thetransmission. Instead, a cable or wire harness adapted to carryelectrical signals (or an equivalent wireless protocol) may be used toprovide a command signal to the electric motors based upon a position ofthe handle. For example, the handle may include a position sensor (e.g.,linear variable differential transducer) or similar device that mayconvert a physical position of the handle into an appropriate electricalsignal that is ultimately provided to the electric motors. In someembodiments, a microcontroller may be provided to receive, as inputs,the signals representing the position of the handle. The microcontrollermay then process these inputs and produce corresponding output commandsto the electric motor(s).

Accordingly, various bidirectional transmission configurations, nowknown or later developed, are certainly contemplated within the scope ofthis disclosure.

While described above in the context of the handle 36′ of FIG. 5 , thoseof skill in the art will recognize that the handle 36 of FIG. 2 couldalso be utilized with slight modification with the mower 300. Moreover,control systems other than the handles 36 and 36′ are also contemplated.For example, FIG. 8 illustrates a mower 400 having a handle 426 thatincorporates two independently movable control members, e.g., first andsecond bails 435 and 436. The bails 435 and 436 are each movable betweena neutral position (corresponding to a neutral mode of the drivesystem), and an engaged position (corresponding to a powered mode of thedrive system). The bails may be connected by cables 382 and 384,respectively, to the transmission 360 (not shown in FIG. 8 , but seeFIG. 7A). As a result, movement of the bail 435 from its neutralposition to its engaged position translates the cone gear 372 to theright in FIG. 7A, resulting in forward mower propulsion (e.g., forwardpowered mode), while movement of the bail 436 from its neutral positionto its engaged position translates the cone gear 372 to the left in FIG.7A, resulting in reverse mower propulsion (e.g., reverse power mode). Inone embodiment, the engaged position of both bails is achieved bypivoting the bail (about the handle) until it rests against the crossmember 430 as indicated in broken lines in FIG. 8 .

The bails 435, 436 may include an interlock that prevents engagement ofone bail unless the other is in a neutral position. In otherembodiments, the diametrically opposing forces applied to the cone gear372 by the cables 382 and 384 (see FIG. 7A) may effectively negate theneed for such an interlock as the bail with the highest operatorengagement force will determine the direction/speed of mower propulsion.

As indicated above, the mower 300 may include the single forward/reversetransmission 360 (or 1360, 1462) at the rear axle to effectively providedriving power to the rear wheels 310. Providing both forward and reverseoperation at the rear axle is beneficial as, for example, the rearwheels typically bear a substantial portion of the mower weight andfurther allow for both forward and reverse propulsion even when thefront wheels 308 are lifted off the ground (e.g., during a turn).However, the forward/reverse transmission 360 (or 1360, 1462) couldalternatively be located at the front axle in other embodiments. Stillfurther, the mower 300 could provide a forward/reverse transmission atboth front and rear axles (see, e.g., broken line transmission 360 inFIG. 6 ), or a forward/reverse transmission at one (e.g., rear) axle,and a forward-only transmission at the other (e.g., front axle). Thelatter configuration would provide not only powered forward and reversepropulsion, but also all-wheel drive when operating in the forwarddirection.

FIG. 9 illustrates a mower 500 in accordance with another embodiment ofthis disclosure. The mower 500 may be similar in many respects to themower 2, 2′, 300, and 400 already described herein. However, the mower500 differs in that the two front wheels 508 each form part of a casterassembly 509 having a caster arm rotationally connected to the deck sothat each front wheel assembly, and thus, its associated front wheel, ispermitted to caster or rotate about a vertical caster axis 511 relativeto the deck 6. With forward/reverse propulsion provided by the rearwheels 510, castering front wheels 508 may provide the mower 500 withimproved maneuverability by, for example, reducing or even eliminatingthe need to lift the front wheels during turns. The mower 500 mayinclude any one of the handles described elsewhere herein.

While various traction drive configurations are described andillustrated in FIGS. 1-9 , those of skill in the art will understandthat other embodiments are certainly possible without departing from thescope of this invention. Moreover, features of the various embodimentsdescribed may be combined/substituted with one another to produce yeteven additional embodiments. Accordingly, the embodiments described andillustrated herein are exemplary only.

During reverse mower operation, the force vector applied by the operatorto the mower handle (e.g., which results in an applied moment to thehandle about the handle/deck attachment point) may reverse. Thisreversal may ultimately result in a downward force being applied to themower handle. In some instances, this downward force may cause the frontof the deck to lift upwardly. As described below, embodiments of thepresent disclosure may address such lifting by utilizing a handle thatprovides a degree of float during mower operation.

FIGS. 10A-14 illustrate a walk power mower 200 in accordance withanother embodiment of the present disclosure. With the exceptions notedbelow, the mower 200 may be mostly identical to the mower 2 (or 2′ or300) already described herein. For example, the mower 200 may include acutting deck 204 that may be self-propelled, i.e., it may include avariable speed traction drive system having one or more transmission(s)carried by the deck as described herein. The drive system may be capableof selectively providing driving power to one or more of the wheels inboth a forward and a reverse direction. Alternatively, the mower 200 mayincorporate a conventional transmission (e.g., rear-wheel drive,front-wheel drive, or all-wheel drive) that is capable of selectivelyproviding driving power to one or more of the wheels in only a single(e.g., forward) direction. For brevity, aspects of the mower 200 thatare either commonly known in the art, or that are already describedherein above, are not further described below.

As shown in FIGS. 10A-10B, the grass cutting deck 204 is supported uponthe ground 203 by a front wheel (e.g., a pair of ground-engaging frontwheels 208) and a rear wheel (e.g., a pair of ground-engaging rearwheels 210). Again, the traction drive system may drive at least one ofthe front wheels and/or rear wheels forwardly to propel the mower 200 asit traverses the ground 203 in a forward direction, while the same ordifferent wheel(s) may optionally be driven rearwardly to propel themower in the reverse direction as already discussed herein. In otherembodiments, the wheels of the mower may be undriven, i.e., the mowermay move under operator push-power only.

The deck 204 may further support a prime mover 212 such as an electricmotor or gasoline-powered engine. The prime mover may power not only thedrive wheels of the mower, but also a cutting blade 16 (see FIG. 3 )operable to rotate within the deck.

A handle 226 extends upwardly and rearwardly from the deck 204 as shownin FIGS. 10A-10B. As with the handle 26 of the mower 2, the handle 226may include a pair of laterally spaced-apart and parallel handle membersor tubes 228 extending upwardly and rearwardly from the cutting deck.Each handle tube includes an upper end forming a grip area, e.g., crossmember 230 and/or handle grip 232. Lower ends of each handle tube 228may be pivotally attached to the deck 204, e.g., to a rear portion ofthe deck. While shown as incorporating two parallel handle tubes, mowerswith handles formed from a single handle member or tube are alsocontemplated.

The handle 226 of the exemplary mower 200 may include a U-shaped handlegrip 232 having a pair of laterally spaced legs 234 connected by anupper cross bar 236 at or near the upper ends of the handle members. Aswith the mower 2, legs 234 of the handle grip 232 may be telescopicallyattached near the upper ends of the handle tubes 228 for slidingmovement (translation) relative thereto. Thus, handle grip 232, like thegrip 32 described above, forms a control system or member slidabledownwardly (and optionally upwardly) on the handle tubes 228 as the userwalks forwardly (and optionally, rearwardly) while gripping the crossbar 236 with the user's hands. That is to say, the control member of thehandle 226 is operable to engage the variable speed traction drivesystem to selectively propel the cutting deck 204 in one or both of theforward and reverse directions in a manner already described herein withrespect to the mowers 2 and 2′.

Of course, in other embodiments, the handle 226 may include analternative control member for interfacing with the traction drivesystem to control mower propulsion, or it may completely lack any suchcontrol member/traction drive system (i.e., when configured as apush-powered mower).

The lower ends of the handle tubes 228 may pivotally attach to the deck204 such that the handle 226/handle tubes 228 may pivot about ahorizontal transverse pivot axis 250 (e.g., an axis that is transverseto a direction of forward or reverse travel of the deck) as shown inFIG. 11 . To accommodate this pivotal connection, the mower 200 mayinclude left and right upright float plates 252 associated with the leftand right handle tubes 228, respectively. The plates 252 may each definean aperture operable to receive a fastener (e.g., pin/nut 254) passingthrough an aligned aperture in its associated handle tube 228. Thepins/nuts 254 thus define the pivot axis 250 about which the handle(e.g., handle tubes) may pivot.

Each handle tube 228 may also include a handle latch 256. Each latch mayinclude a lever 258 that is rotatable (e.g., 90 degrees) to allowextension and retraction of a latch pin 260. In the operating positionillustrated in FIG. 11 , each pin 260 may be engaged with a slot 264formed in the associated plate 252. The slots constrain the handle 226(handle members 228) not to a singular position like the notches 262(described below), but rather allow the handle 226/tubes 228 to pivot,relative to the deck 204, between: an upper stop 266 a (upper end of theslot 264) corresponding to the handle being in a first operatingorientation R (see FIG. 14 ); and a lower stop 266 b (lower end of theslot) corresponding to the handle being in a second operatingorientation B (see also FIG. 14 ). The upper and lower stops 266 a, 266b thus define an operating range of pivotal motion of the handle (i.e.,of the handle tubes). In one embodiment, the operating range of pivotalmotion is at least about 5 degrees (i.e., about 5 degrees or more) ofrotation about the pivot axis 250. For example, in some embodiments, arange of about 5-20 degrees, or a range of about 8-12 degrees, iscontemplated.

By retracting the latch pins 260, the handle 226/handle members 228 mayalso be moved from the operating orientations to a third or storageorientation S shown in broken lines in FIG. 14 . In the storageorientation S, the handle 226/handle tubes 228 is positioned generallyvertically to reduce the footprint of the mower during non-use. Thehandle 226 may be latched in the storage orientation by extending thepins 260 into engagement with associated notches or openings 262 formedon the plates 252 (see FIG. 11 ). As one can appreciate, the storageorientation S is outside of the operating range of pivotal motiondefined by the slots 264 and stops 266 a, 266 b. While shown as placingthe handle 226/handle members 228 in a generally vertical storageposition, such a configuration is not limiting. For instance, otherembodiments may locate the notches 262 (or, alternatively, provide anadditional set of notches 262) to allow for handle 226/handle member 228storage at a different angular orientation. One such orientation mayplace notches 262 such that the handle 226/handle members 228 extendforwardly and generally parallel to the ground 203 (see FIG. 14 ) whenin a storage orientation S′.

As shown in the exploded view of FIG. 12 , each plate 252 may rotatablyattached to an upright flange 253 of the mower deck via its associatedpin/nut 254 such that it may rotate about the transverse pivot axis 250.To rotationally secure each plate 252 in place relative to itsassociated flange 253, a fastener 255 and threaded knob 257 may beprovided. The fastener 255 may be inserted through an aperture 259 inthe flange 253 and into one of two (or more) holes 261 a, 261 b formedin the bracket 252. By pivoting the plate until the appropriate hole 261a, 261 b aligns with the aperture 259, the mower may provide varyinghandle operating heights to accommodate a broad range of users. Once thefastener 255 is inserted through the desired hole 261 a or 261 b of eachplate 252, the threaded knob 257 may be secured to the fastener 255 tolock the plate 252 in place.

With reference now to FIGS. 11-14 , the mower 200 may also include ahandle float system adapted to bias the handle (e.g., the handlemembers) toward the upper stop 266 a. In one embodiment, the floatsystem includes a resilient member, e.g., left and right resilientmembers 272, operatively positioned between each lower stop 266 b of thecutting deck and its respective handle member 228. For example, in theillustrated embodiment, the left and right resilient members 272 may bepositioned such that they abut a lower side of the left and right handletubes 228, respectively, when the handle is at rest (when the handle isin the operating orientation R (see FIG. 14 ) and no user loads areapplied to the handle). In some embodiments, the resilient members 272may bias the tubes 228 against their respective upper stops 266 a.However, in other embodiments, the resilient members may be configuredto bias the handle members to a location that is at or near (e.g.,slightly short of) the upper stops when the handle is at rest.

The term “resilient member,” as used herein, includes most any devicethat is able to deform, displace (e.g., displace a contained fluid),distort, or contract under load, and then spontaneously return to (ornear) its original configuration when the load is removed. Thus, inaddition to the neoprene cylinder configuration described below, otherresilient members, e.g., a pneumatic spring, a mechanical or fluidicshock absorber, etc., are also contemplated within the scope of thisdisclosure.

To secure each resilient member 272 in place, the mower deck 204, e.g.,the plates 252, may each define a seat 274. In the illustratedembodiment, each seat is formed by a bent tab of its associated plate252 (see FIG. 12 ). The seat 274 may define an aperture adapted toreceive an integral threaded stud 276 of the member 272 as shown inFIGS. 12 and 13 . The stud 276 may pass through the aperture in the seat274 and be secured relative to the plate 252 with a nut 278.

Each member may be constructed of a resilient elastomeric material. Forexample, while not wishing to be bound to any specific configuration,each member 272 may be a neoprene disk or cylinder having a durometer of60 Shore A. In the illustrated embodiment (see, e.g., FIG. 13 ), thecylinder may have a height of about one inch and a diameter of about1.25 inches. However, members of other materials, hardness, size, andgeometry are certainly contemplated.

During operation of the mower 200 over the ground 203, the handle 226may be used to control forward propulsion at already described abovewith reference to the mower 2 and 2′. For example, as shown in FIG. 14 ,the user may apply a force 280 that either: displaces the handle grip232 downwardly along the handle tubes 228 to engage the traction drivesystem; or, where the mower is push-powered, pushes against the crossmember 230 sufficiently to move the mower forwardly. In the case of theformer, as the user walks forwardly and applies this input force 280 tothe handle grip 232, the handle grip moves from a neutral position(wherein the traction drive system is inactive), to a first engagedposition, causing one of the transmissions to engage and propel themower in the forward direction.

As this user-applied force 280 is offset from the deck 204, it may alsoproduce a pivoting force on the handle 226/handle tubes 228 (about theaxis 250 (see also FIG. 11 )) in a clockwise direction 282 as shown inFIG. 14 . However, the upper stop 266 a of the slot 264 (see also FIG.11 ) will effectively limit this pivotal movement of the handle(relative to the deck 204). As stated above, however, some minimalpivotal movement in the direction 282 may be accommodated before contactoccurs between the pin 260 and the upper stop 266 a. However, once thehard stop 266 a is contacted, further movement of the handle 226(relative to the deck) in the direction 282 may be constrained.

When the user instead applies a pulling input force 284 to the mowerhandle 226 (e.g., directly to the handle grip 232) in a reversedirection, the handle grip 232 may move upwardly along the handlemembers from the neutral position to a second engaged position. In thesecond engaged position, the traction drive system may activate forpropulsion in the reverse direction. Moreover, as this reverse motionoccurs, the handle 226/handle members 228 may pivot (about the pivotaxis 250) in a counterclockwise direction 286, i.e., toward the lowerstop 266 b (see FIG. 11 ) corresponding to the second operatingorientation B of the handle. As this pivotal movement occurs, eachhandle tube 228 may compress and resiliently deform its associatedmember 272. As a result, the moment of the handle 226 is reacted, atleast initially, by compression of the members 272, allowing substantialdownward movement of the handle (e.g., cross member 230/hand grip 232)to occur and be isolated (at least initially) from corresponding upwardmovement of the mower's front wheels 208. Of course, once the membersbottom out on the hard stop 266 b (see FIG. 11 ), further movement ofthe handle 226 in the direction 286 may begin to elevate the mower'sfront wheels 208.

With a mower 200 like that described herein incorporating two neoprenemembers 272 as described above, the handle 226 may pivot about its pivotaxis 250 (in the direction 286) about 10 degrees from its at restposition R (shown in solid lines in FIG. 14 ) to a bottom position Bbefore the front wheels 208 would begin to rise. While varyinggeometries are possible, one embodiment of the mower 200 may use ahandle that is roughly 32 inches long (measured from a centerline of thecross member 230 to the pivot axis 250). With this construction, thecross bar 230 may move a linear distance (e.g., along an arc 288) ofapproximately 5-10 inches, e.g., 6 inches, as the handle tubes move fromthe upper stop 266 a to the lower stop 266 b (see FIG. 11 ). Of course,depending on the stiffness/configuration of the members, the weight andweight distribution of the mower, and the magnitude of the force 284,the members may effectively form the lower stops. That is to say, themembers 272 may reach a maximum deflection before the pins 260 contactthe lower stops 266 b. However, in other embodiments, the members maycontinue to compress up and until the lower stops 266 b are contacted bytheir respective pins 260.

Floating handles such as those described herein may thus allow at leastsome degree of downward movement of the handle to occur without causingassociated lifting of the front wheels. As a result, mowers that utilizea sliding control member to initiate rearward propulsion (e.g., like thehandle 226 described herein) may permit rearward/downward handlemovement without causing front wheel lifting (at least during typicaland expected operation). This advantage may be especially useful formowers that incorporate reverse drive at the front wheel axle. However,even for mowers that provide no powered reverse operation, floatinghandles in accordance with embodiments of the present disclosure maystill assist in keeping the front wheels in contact with the groundduring reverse pulling of the mower.

While described herein in the context of a four-wheel mower, such aconfiguration is exemplary only. For instance, it is contemplated thatembodiments of the present disclosure may find application to mowershaving tri-wheel configurations (e.g., having only a single front wheeland/or a single rear wheel), as well as to most any othermulti-wheel/multi-axle configuration. Yet further, mowers usingground-engaging members other than wheels (e.g., a rear roller) are alsopossible. Still further, embodiments of the present disclosure may findapplication to mowers entirely lacking physical ground-engaging members.For example, hover mowers, which float above the ground on a cushion ofair generated by the mower, may benefit from the concepts (e.g., thebiased handle) described herein. Those of skill in the art will furtherrealize that embodiments of the present disclosure may also findapplication to walk-behind power equipment other than lawn mowers havinga ground-traversing tool housing other than a cutting deck including,for example, aerators, wheeled debris blowers, cultivators, and thelike.

Various modifications will be apparent to those skilled in the art.Thus, the scope of this invention is not to be limited to the details ofthe various embodiments described herein, but shall be limited only bythe appended claims, and equivalents thereof.

What is claimed is:
 1. A power equipment unit comprising: a housingconfigured to traverse a surface in both a forward direction and anopposite, reverse direction; a prime mover carried by the housing, theprime mover operatively connected to a tool associated with the housing;a bidirectional variable speed traction drive system carried by thehousing, the traction drive system configured to selective propel thehousing over the surface; and a control system comprising: a handle gripoperatively connected to the traction drive system and movable relativeto a handle member extending upwardly and rearwardly from the housing,wherein the handle grip is configured to activate the traction drivesystem to move the housing in the forward direction when the handle gripis moved in a first direction, and wherein the handle grip is configuredto activate the transmission to move the housing in the reversedirection when the handle grip is moved in a second direction oppositethe first direction; and a position sensor associated with either orboth of the handle grip and the handle member, wherein the positionsensor is configured to produce an electrical signal indicative of aphysical position of the handle grip relative to the handle member, andwherein the electrical signal is configured to generate a correspondingoutput command to the traction drive system.
 2. The power equipment unitof claim 1, wherein the traction drive system receives power from theprime mover.
 3. The power equipment unit of claim 1, wherein thetraction drive system comprises one or more electric motors independentof the prime mover.
 4. The power equipment unit of claim 1, wherein theprime mover comprises an electric motor.
 5. The power equipment unit ofclaim 1, wherein the housing comprises a cutting deck and the toolcomprises a rotating cutting member.
 6. The power equipment unit ofclaim 1, wherein movement of the handle grip relative to the handlemember comprises translation of the handle grip along the handle member.7. The power equipment unit of claim 1, wherein the traction drivesystem comprises: first and second rear wheels each configured as drivewheels; and first and second electric motors coupled to the first andsecond rear wheels, respectively.
 8. The power equipment unit of claim1, further comprising a controller configured to: receive the electricalsignal from the position sensor; and generate the output command to thetraction drive system.
 9. A walk-behind power equipment unit comprising:a housing supported upon a surface, the housing configured to traversethe surface in both a forward direction and an opposite, reversedirection; an electric motor associated with the housing, the electricmotor configured to provide power to a tool connected to the housingduring operation of the power equipment unit; a bidirectional, variablespeed traction drive system carried by the housing, the traction drivesystem configured to selective propel the housing over the surface atleast during operation of the power equipment unit; and a control systemcomprising: a handle grip operatively communicating with the tractiondrive system and movable relative to a handle member extending upwardlyand rearwardly from the housing, wherein the handle grip is configuredto activate the traction drive system to propel the housing in theforward direction when the handle grip is moved in a first direction,and wherein the handle grip is configured to activate the transmissionto propel the housing in the reverse direction when the handle grip ismoved in a second direction opposite the first direction; and a positionsensor associated with either or both of the handle grip and the handlemember, wherein the position sensor is configured to produce anelectrical signal indicative of a physical position of the handle griprelative to the handle member, and wherein the electrical signal isconfigured to generate a corresponding output command to the tractiondrive system.
 10. The power equipment unit of claim 9, wherein theelectric motor is configured to provide power to the traction drivesystem.
 11. The power equipment unit of claim 9, wherein the tractiondrive system comprises one or more electric propulsion motorsindependent of the electric motor.
 12. The power equipment unit of claim9, wherein the tool comprises a rotating cutting member.